Slate-frame



(No Model.)

D. SGRYMGEOUR.

SLATB FRAME.

No. 426,145. PatenteApr. 22, 1890.

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*rn rares Arent OFFICE.

DAVID SCRYMGEOUR, OF FOXBOROUGII, MASSACHUSETTS.

SLATE-FRAM E.

SPECIFICATION forming part of Letters Patent No. 426,145, dated April 22, 1890.

Application lcd September Z, 1889. Serial No. 322,747. (No model.)

To @ZZ whom, t may concern:

Be it known that 1, DAVID ScRrMeEoUr., a citizen of the United States, residing at Foxborough, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Slate-Frames; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanyin g drawings, and to figures of reference marked thereomwvhich form a part of this specication.

This invention relates to slates or Writingtablets to be employed for educational or business purposes, but more particularlyv in schools.

My improvements consist in the construction of the slate-frame, whereby the latter is not only prevented from being broken, but is rendered noiseless. Furthermore, the cost of manufactureis cheapened. This is effected in constructing the parts in such manner that a slate of any size can readily be fitted with a frame.

Briefly described, my invention consists in a slate-frame which is te Le composed of eight members, the side and end pieces to be similar in cross-section and differing merely in their len gth, While the remaining` four pieces, right angled, forming the corners and locking the side and end parts together, are identical in shape and construction. Said corners are adapted to slide preferably Within and telescope upon the extremities of the adjacent side and end pieces and serve to unite them by interlocking fastenings, to he hereinafter described. v'lhus it is evident that the corner members are of such shape, rightangled, that they will fit a slate of any size, While the side and end pieces are cut from metallic strips of a length required to fit a slate of any dimensions desired. In this way the cost of making a slate-frame is very much lessened.

The drawings accompanying this specification represent in Figure l a longitudinal section horizontally through the frame, and Fig. 2 is a side elevation of a slate-frame embodying my improvements. Fig, .3 is an enlarged view showing the interlocking,r fasten- Vfor writing upon.

ing. Fig. -l is a cross-section of the slateframe, showing one of the many forms which may be employed.

In the carrying out of my invention I have shown at 2 a thin plate or tablet of mineral Such plate may be of any desired size, but preferably rectangular in shape. To prevent it from breaking, which otherwise would happen incident to a fall or blow or from unequal pressure upon it laterally, a frame 8, which surrounds its perimeter, is necessary. Said frame must embody certain features. It should be very stiff and strong, likewise noiseless. To combine all such characteristics7 and, further, to render it cheap and easily manufactured, I propose to make said frame of metal, to be composed of side and e'nd pieces i 4 5 5, respectively. These members of the frame are to be similar in general cross-section, preferably U shaped, or approximately so, in general cross-section, but, with the ends drawn together or converging, as shown in Fig. let; or the sides of the metal may be mitered, as described in Letters Patent issued to me January 2i, 1888. To pro duce the side and end members of the frame, a long strip or band of metal may be used and passed between rolls of such form as to give the desired shape in crosssection. Said band is then in readiness to be cut into lengths req uisite to form the sides and end pieces of a slate-frame. As before stated, the opposite edges of this metal strip are bent together, so that when the separate pieces are applied to the perimeter of the Writing-tablet said edges hug and tightly grasp the tablet and prevent any rattle. As shown inthe drawings, the side and end members are eut of a length to suit the size of the slatemthat is, just equal to the length and Width. of the tablet to be framed. The co1'nerpieces G G, similar in cross-section, are now formed, their extremities being' at right angles, While the central portion is rounded to form an oval corner at the apex of the angle. Said pieces are adapted to slide Within the extremities of the side and end members, which are provided with a spur 7, struck integrally therefrom to engage a slot S, cut in the side and end pieces. Said interlocking spurs are formed preferably upon. the bend of the metal interiorly of the ends and sides to engage holes in the corner menrl IOO other modifications can readily be substitutedV for such as are herein shown.

To apply a frame constructed as above premised, by preference the side pieces previously covered with some flexible material 9 are adjusted in position. The corners are now placed in engagement with the end parts. This being done, theffree extremities of the corners are now aligned with the sides and thrust between the latter and the edge of the slate. As they enter, the end piece is adjusted over the edge of the slate and said end member and the two corners are driven home, the spurs 7 interlocking` with the slots 8 S in the sides 4 4:. Similarly the opposite end and corners are positioned and united with the adjacent extremities ofthe sides, when the slateframe is then complete, being securely fastened at all points asif it were made from a single piece or band of metal.

Io render the slate-frame noiseless when completed, I have covered the end and side members of the frame with some flexible material 9-such as rubber cloth-which can be easily cleansed. The corner parts G 6, however, are to be covered with vulcanized rubber l0, and of a thickness greater than the material which covers the rest of the frame.

slate is supported upon said corners as buffers, and as the latter receive all the shocks or blows incidental in the handling of the slate the latter is not liable to be broken or cracked.

That I desire to claim is Thus then l. A slate-frame composed of the followingdescribed members: four straight 'strips of metal or equivalent material similar in crosssection,which serve as end and side pieces to receive and inclose the perimeter 0f the Writ- ,ingtablet, four right-angled piecesor corners adapted to telescope Within said end and side pieces, and fastening elements formed upon the extremities of each of said members, which serve to lock all the members rigidly together as a unit, substantially as herein described.

2. A Vmetallic slate frame composed of straight side and end pieces U-shaped inY Yparts and with rubber vulcanized upon the corner members, substantially as shown and stated.

3. In Combination With a writing-tablet, a metallic frame consisting of'four members U f shaped in general cross-section to receive the perimeter of said tablet, four corners which telescope Within and unite the end and side members, an external flexible covering for the side and end pieces, and a vulcanized thicker covering of rubber upon said corners, all operating substantially as herein specified.

In testimony whereof I affix my signature in presence of two witnesses.

DAVID SGRYMGEOUR. Vitnesses: Y'

H. E. LODGE,

WILLIAM' Fos'rER. 

